package com.students.config.filter;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

/*
* 自定义Authority解析器:
* 反序列化
* */
public class CustomAuthorityDeserializer extends JsonDeserializer {
    @Override
    public Object deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
        ObjectMapper mapper=(ObjectMapper) jsonParser.getCodec();
        JsonNode jsonNode=mapper.readTree(jsonParser);

        List<GrantedAuthority> grantedAuthorities=new LinkedList<>();
        Iterator<JsonNode> elements=jsonNode.elements();
        while (elements.hasNext()){
            JsonNode next=elements.next();
            JsonNode authority=next.get("authority");
            grantedAuthorities.add(new SimpleGrantedAuthority(authority.asText()));
        }
        return grantedAuthorities;
    }
}
